Obsolete — sourcing through independent channels
The 0603SFP350F/32-2 is listed as obsolete by Littelfuse, meaning the manufacturer no longer produces it. A board-spin or parametric substitute evaluation is required if a direct drop-in is not found in the surplus channel.
Protection profile — 3.5 A, 32 VDC, 50 A interrupt
Rated 3.5 A continuous at 32 VDC, this SFP-series fuse opens a fault circuit with a breaking capacity of 50 A at the rated voltage — sufficient for low-voltage DC rails where the prospective short-circuit current stays under that ceiling. The melting I²t of 1.1 A²s defines the energy let-through before the element clears. This figure is the key coordination parameter: downstream semiconductors or PCB traces must survive the I²t pulse without damage, so the fuse's 1.1 I²t sets the minimum withstand requirement for the protected components. DC cold resistance measures 0.022 Ohms. At 3.5 A the voltage drop is roughly 77 mV, and the I²R self-heating at rated current is about 0.27 W — negligible in free air but worth derating in a densely populated 0603 layout.
0603 footprint and board integration
Housed in the standard 0603 (1608 metric) surface-mount package — 1.60 mm x 0.81 mm x 0.81 mm — the fuse occupies the same land pattern as a chip resistor or capacitor of the same size. The reflow profile follows the solder paste supplier's recommendation for the pad geometry; no special handling beyond standard SMT assembly is required. The operating temperature range spans -55°C to 125°C, covering industrial and military-temperature environments. The fuse's current-carrying capacity derates above 25°C ambient; the datasheet's derating curve should be consulted for the actual trip threshold at the application's maximum ambient.